Over at Bible and Interpretation, Craig Evans has a short article on How Long Were Biblical Manuscripts in Use. The blurb reads:
I speculated that if the Gospel of Matthew were published and circulated in 75 CE and if it and some of the first copies of it were in use as long as the manuscripts in the collections and libraries studied by Houston were in use, then some of these manuscripts could still have been in circulation, being read, studied, and copied, as late as the end of the second century and perhaps even on into the third century. This means that New Testament autographs and first copies could still have been available when our oldest extant papyri manuscripts (e.g., P45, P46, P66) were produced. If still in circulation and being read and copied, the autographs and first copies would have continued to give shape to the text. In a sense, then, the gap between autograph and extant manuscript is bridged.